South Dakota State University Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange Agricultural Experiment Station Technical Bulletins SDSU Agricultural Experiment Station 1949 The irW eworms (Elateridae) of South Dakota H.C. Severin Follow this and additional works at: http://openprairie.sdstate.edu/agexperimentsta_tb Recommended Citation Severin, H.C., "The irW eworms (Elateridae) of South Dakota" (1949). Agricultural Experiment Station Technical Bulletins. 20. http://openprairie.sdstate.edu/agexperimentsta_tb/20 This Article is brought to you for free and open access by the SDSU Agricultural Experiment Station at Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. It has been accepted for inclusion in Agricultural Experiment Station Technical Bulletins by an authorized administrator of Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. For more information, please contact [email protected]. Technical Bulletin No. 8 June 1949 THE WIREWORMS (Elateridae) OF SOUTH DAKOTA !Jntomology-Zoology Department ·1 1 AGRICULTURAL EXPERIMENT . STATION South Dakota State College of Agnculture and Mechanic Arts Brookings, South Dakota THE WIREWORMS (Elateridae) OF SOUTH DAKOTA Entomology-Zoology Department AGRICULTURAL EXPERIMENT STATION South Dakota State College of Agriculture and Mechanic Arts Brookings, South Dakota Table of Contents PAGE In trod uc tio n _______________ ------------------------------------------------------------------------------------ . 3 Description of beetles ------------------------------------------------------------------------------------ 3 Life cycles and seasonal cycles -------------------------------------------------------------------- -- 4 Description of larvae _______ ----------------------------------- ___ _____ __ ___ __________________ ___________ 5 Economic importance and damage done by larvae -------------------------------- 6 Habitats preferred by different species ------------------------------------- ·---------------- 7 Co 11 ectin g beetles ------------------------------------------------------------------------------------- ----·· 7 Co 11 ec ting larvae ____________________ ----------------------------------- ·___ ---------------------------- _____ 7 Control measures ----------------------------------------------------------------------------------------- 8 Rotation of crops ----------------------------------------- '------------------------------------------ 8 Summer and early fall plowing ---------------------------------------------------------- 8 Flooding soil to kill wireworms ---------------------------------------------------------- 9 Drying soil to kill wireworms -------------------------------------------------------------- 9 Chemical control of wireworms ---------------------------------------------------------- 9 Trapping wireworms by means of bait ---------------------------------------------- IO Killing wireworms by means of poisoned bait ---------------------------------- IO Acknowledgements ------------------------------------------------------------------ _____________ . ___ 10 Species of Elateridae collected in South Dakota -------------------------------------- 11 THE WIREWORMS (Elateridae) of South Dakota 1 By H. C. SEVERIN Introduction The Elateridae constitute a family of beetles that are commonly known as elater­ beetles, click-beetles, snapping-beetles, or skip-jacks and in the larval stages are called w1reworms. • Nearly 7,000 species of Elateridae have been described as occurring in the world. Of these, nearly 700 are found in America north of Mexico. In this report, 67 species and varieties are recorded from South Dakota, and these species are grouped into 22 genera. The species of Elateridae that are recorded in this bulletin as occurring in South Dakota do not form a complete list of the beetles for this state. In fact, it is believed by the writer that this list represents less than 50 per cent of the species that will ultimately be found within the state. Fig. 1. A click beetle, Melanotus fissilis (Say) about five times natural size. From Ill. Nat. Bist. Sur. D escription of Beetles Most of our South Dakota species of are black, a few are spotted and an occa­ click-beetles are small or of medium size sional species is banded. One species and range from % to % of an inch in ( two varieties) is conspicuously marked length. An occasional small species mea­ on the pronotum with two large black sures Y4 of an inch or less in length while eye spots surrounded with grayish white at the other extreme the giants may mea­ margins. The beetles are recognized by sure 1 Yz inches in length. The majority the following characters: of the South Dakota species are of a uni­ form of body, elongate oval, usually form brown color. Many are gray, some tapering somewhat toward each end; 1£ntomologist , South Dakota Agricu ltural Experiment Station . the posterior end at times pointed; 4 South Dakota Experiment Station Technical Bulletin 8 length of body three to five times that front of the head; of width; dorsum of body and elytra mandibles small, retracted and bifid; smooth, punctate, striated, rugose, legs short; hairy or scaled; head small and partly coxae of first pair of legs small and sunken into prothorax; prothorax rounded; coxal cavities of prothorax loosely joined to mesothorax so that open behind; the prothorax may be readily moved hind coxae large, transverse and con­ up and down; a prosternal spine ex­ tiguous, or nearly so, along the mid tends backward from the prothorax line and grooved for the reception of and fits into a socket in the mesoster­ the femora; um; it is largely due to this spine and tibiae slender; socket that the beetles are able to flip their bodies up into the air when they tarsae 5-jointed on all legs; happen to alight on their backs; elytra covering the body in most spe­ antennae I I-jointed, more or less ser­ cies; wings well developed, enabling rate, widely separate and -fastened in the insects to fly; small pits in front of the compound abdomen with five visible sterna, the eyes and underneath the margin of the first and second not grown together. Life Cycles and Seasonal Cycles The Elateridae pass through four radi­ worms hibernate. Pupation takes place cally different stages in completing their usually late in the summer or early fall, and or:dinarily the pupal stage extends life cycle, namely, egg, larva, or wire­ over a period of three or four weeks. worm, pupa and beetle. The beetles are the adult insects, the females of which lay eggs. From the eggs hatch the larvae or the wireworms. The wireworms, when a ~o 0 0 0 full-grown, transform to pupae and these 0 give rise to the beetles. 0 ~ The duration of the life cycle of the C) 0 various species of Elateridae is by no means identical. Some species complete C) 0 0 0 their entire life cycle in one year, while 0 ~ others require as much as five years. The (:) 0 0 ()0 () () \) eggs of most of the species of Elateridae () are laid in the spring by beetles that 0 hibernated over the winter, but there are some species that lay their eggs in the fall Fig. 2. Eggs (six times natural size) of the of the year. In the latter case the eggs Pacific Coast Wireworrn, Limonius canus Lee. hatch later in the fall and the young wire- After M. C. Lane. The Wireworms 5 (L a, Fig. 4. Terminal segment of body of wire­ worm Drasterius dorsalis (Say) much enlarged. Fig. 3. A corn wireworm, Melunotus commu­ From Ill. Nat. Hist. Sur. nis (Gyll.): a. Adult beetle; b. larva or wire­ worm; c. side view of last segment of larva; d. pupa. All enlarged. After Chittenden. Fig. 5. A corn wireworm, Melanotus cribulosus (Lee) about three times natural size. From Ill. Nat. Hist. Sur. Description of Larvae The larvae of the Elateridae are com­ The head is provided with mouth monly called wireworms because of their parts which are of the chewing type. superficial. resemblance to a short piece Eyes may, or may not, be present, though of shiny copper or bronze wire. In color, they are difficult to see even when pres­ most of the South Dakota wireworms ent. The antennae are small and short. vary from light yellow to light or even Immediately back of the head is the thor­ dark brown. The body is long and ax. This body division consists of three wormlike, cylindrical or Battened and segments each of which is provided with covered by a comparatively hard skin. a pair of well-developed legs. The abdo­ Most of the native species of wireworms men follows the thorax and consists of when full-grown measure from Yz to 1 )4 ten legless segments, nine of which are inches in length. An occasional species visible from above. The ninth abdominal measures about % of an inch in length segment varies much in di fferent species when full-grown, and one species ( two of wireworms and furnishes some of the varieties) measures more than 1 Yz characters that are used in the identifica­ inches. tion of the species. 6 Soutb Dakota Experiment Station Tecbnical Bulletin 8 Economic Importance and Damage Done by Larvae Most of the larvae of the South Dakota species of Elateridae feed upon plant ma­ terials, but there are some that seem to be entirely predaceous. Even though a spe­ cies may be classed as feeding on plant materials, it may not be of economic im­ portance, for it may feed on decaying wood, leaf litter, etc. In the latter case, however, they may be predaceous, for they may be feeding on larvae in the wood or leaf litter.